Conversion of carbohydrates to products of higher oxidation



Patented Aug. 9, 1932 UNITED/STATES PATENT OFFICE WILLIAM E. STOKES, OF ROCKVILLE CENTER, AND ARNOLD H. PETER, OF NEW YORK, N. Y., ASSIGNOBS TO ROYAL BAKING POWDER COMPANY, OF NEW YORK, N. Y, A

CORPORATION OF NEW JERSEY CONVERSION OF CARBOHYDRATES TO PRODUCTS OF HIGHER OXIDATION No Drawing. Application filed December tose and cane sugar to tartrate substances and to the oxidation of other carbohydrates, such as cellulose in the form of sawdust.

The formation-of small quantities of tarvtrate substances in the oxidation of carbohydrates by means of nitric acid was observed long ago; and there have been several suggestions of methods and expedients designed to give practical effect to that observation. The methods and expedients heretofore suggested result in the uncertain production of small quantities of tartrate substances with other substances such as, saccharic and, more particularly, oxalic substances, so that the commercial oxidation of carbohydrates hasnot been feasible. By the method and exped1-' ents hereinafter described carbohydrates may be oxidized without obtaining oxalic acid,

with little, if any, saccharic acid, and with yields of tartaric acid sufiicent for commercial success.

The invention comprises the discovery that the introduction of alarge quantity of manganese chloride into a mixture of carbohydrate, nitric acid and water results in obtaining materially different results. The explanation of the observed phenomena is obscure. The fact that the results are not obtained by the introduction of the manganese chloride in catalytic quantities indicates that the action is not catalytic, as does the fact that the introduction of sundry catalyzers does not produce the same results. Certain observations suggest that the manganese chloride may retard or inhibit the formation" of oxalic acid and, in somewhat less degree, saccharic acid, thus permitting theincreased development of tartaric acid. But, pending further research, we avoid attempting any explana- 21, 1925. Serial No. 76,914.

tion. The preferred method of practicing the invention is as follows Carbohydrate, water, nitric acid and manganese chloride are brought together. Deslrable proportions are 100 parts starch, 100 parts water and 100 parts nitric acid, and 20 parts manganese chloride. Strong acid is to be preferred to dilute acid; and acid is preferably added in successive portions o avoid too active reaction and under conditions hereinafter recited. The quantity of manganese chloride may vary within wide limits. We have found that if, instead of 20 parts, 3 parts are used oxalic acid, saccharic acid, and tartaric acid are obtained; with 10 parts there is no oxalic acid but saccharic and tartaric; when the amount is. further increased there is no oxalic and much less interference from saccharic; and further increases vup to 50 parts, seem to produce substantially the same results as about parts.

These substances are preferably allowed to stand at about room temperature until the mixture becomes thin. Then thev are heated,

preferably with stirring, to about 90 C. At

about that temperature the reaction starts and the heat may then be discontinued. within a short time thereafter, about 10 to 15 minutes, the mixture assumes a darker color. Then 100 parts more of nitric acid are added and the mixture again heated to about 90 C. The color again turns darker within half an hour to an hour. Then 100 parts more of nitric acid are added and the mixture is heated to about 40 to at which temperature it is kept for 40 to 50 hours.

The subsequent treatment. depends largely upon the form in which it is desired to obtain the tartrate substance. If cream of tartar is sought, one treatment is todilute the mixture with water, neutralize with an alkali, as potassium carbonate, filter oif the manganese hydrate precipitated thereby and add acetic acid. If tartaric acid is desired soda-ash may be added until the mixture is alkaline, and aftter boiling and'filtering off the manganese hydrate calcium chloride may be added to form calcium tartrate, which may be filtered OE and decomposed as usual to get tartaric acid. a

than those obtained It will'be understood that other hydrates may be substituted for starch 1n the illustration given, and the relative proportions may be much varied. Weaker acid may also be employed, particularly if accompanied by increase in rature m the earlier But the process, substantially as recited in the illustration, has been found to 've as good results as any variations of it th ns far tried, and somewhat better results from some variations. We claim:- I 1. A process for the conversion of carbohydrates to. products of higher oxidation,

comprising bringing together c'arboh drate and nitric acid in'an amount less than t at required for the oxidation, and man ese chloride in an amount suflicient to 111111 1t the formation of oxalic acid, heating the mixture until reaction starts and allowin its 1ngredients to react, adding Ilitl'iOlOl heat ng until reaction again starts, and allow ng further oxidation therewith, then adding more nitric acid, and maintaining the mixture at a tem rature above room temperature and below t e starting temperature of the reaction.

2. A process for the oxidation of carbohydrates, comprising heating a'mixture containing nitric acid in an amounttheoretlcally less than that required for the oxidat on of the carbohydrate, a compound contaimn mannese in an amount sufiicient to inhi it the ormation of oxalic acid and the carbohydrate to be oxidized until reaction starts, and subsequently adding more nitric acid, and maintaining the mixture at a tem' rature above room temperature and below e temperature used to start the reaction.

3. A process for converting a carbohyrate to a product of higher oxidation, comprising causm a carbohydrate and nitric acid to react in t e pmence of a quantity of manganese containin compound equal to weight a; the carbohydrate.

4. A process for the conversion of a carbohydrate to a product of higher oxidation, comprising causing a carbo ydrate and nitric acid to react in the presence of an amount of manganese chloride exceeding 3% by weight of the carbohydrate.

5. A process for the conversion of a carbohydrate to a product of hi her oxidation, comprising causing a carbo ydrate and nitric acid to react inthepresence of an amount of manganese-containing compound exceeding by weight of the carbohydrate.

6. A process for oxidizing a carbohydrate, which com rises treating a carbohydrate with nitric aci in the presence of an amount of manganese chloride exceeding 10% by weight of the substance to be oxidized.

7. A process for converting a carbohydrate to a product of higher oxidation which consists in oxidizing a carbohydrate with nitric about by acid in the presence of a quantity of a man- Eauese containing compound exceeding 8% y weight of the carbohydrate.

' 8. A process for converting a carboh drate to a product of higher oxidation whi comprises oxidizing a carbohydrate with nitric acid in the resence of a quantity of manganese chlori eual to about 20% by weight of the carbohy te.

9. A process for converting a carboh drate to a product of higher oxidation whi consistsmoxidizinga starch withnitric acidin the presence of anamount of a con com und exceeding 3% by weighiof the car hydrate.

10.- drate to a product of higher oxidation which comprises reacting one part of a carbohydrate with one partnitric acid and. one of water in the presence of'.2 part of a compound containing manganese.

11. A process for convertin a carbohydrate to a product of higher oxidation which comprises reacting a mixture containing one part starch, one part of' w-ater, one part of nitric acid and .2 part of'manganese chloride under the influence of heat, then adding one part nitric acid and again reacting under the influence of heat and en uently process for converting a carbohyadding one part of nitric acid and maintaina the reaction mixture at a tem rature ve room temperature and below t 0 starttemperature of the reaction. I process for converting a carbohydrate to a product of higher oxidation which comprises mixing one part of starch, one part water and one part nitric acid and .2 part of manganese chloride, heating to about 90 0., allowing the mixture to react, then adding one part of nitric acid and again heating to 90 C. and allowin the mixture to react and subsequently ad ing one part of nitric acid and heating the mixture to a tem rature of from 40 to C. for a period 0 several hours.

13. A process for the oxidation of whohydrates, which comprises heating a mixture consisting of nitric acid, a compound containing man ese in an amount suficient to inhibit e formation of oxalic acid, and the carbohydrate to be oxidized, until reaction starts, and subsequently maintaining the mixture at a temperature above room temperature and below the starting temperature of the reaction.

14. A process for the oxidation of carbohydrates, which comprises treating a carbohydrate with nitric acid in the resence .of an amount of manganese chlori to inhibit the formation of oxalic acid.

15. A process for the oxidation of carbohydrates, which comprises treating a starch with nitric acid in the presence of an amount of manganese chloride suflicient to inhibit the formation of oxalic acid.

s 8 ing e suflicient 16. A proesa for the oxidation of carbm hydrates, which comprises reacting a carbohydrate with nitric acid solely in the presence of an amount of a manganese-containing compound suflicient to inhibit the formation of oxalic acid.

E. STOKES.

ARNOLD H. PETER. 

